Methods of using foamed settable compositions comprising cement kiln dust

ABSTRACT

The present invention provides settable compositions that comprise water and cement kiln dust. The settable compositions optionally may comprise an additive that comprises at least one of the following group: fly ash; shale; slag cement; zeolite; metakaolin; and combinations thereof. The settable compositions optionally may be foamed with a gas. Methods of cementing also are provided that comprise: providing the settable composition; introducing the settable composition into a location to be cemented; and allowing the settable composition to set therein. The location to be cemented may be above ground or in a subterranean formation.

BACKGROUND

The present invention relates to cementing operations and, moreparticularly, to settable compositions comprising water and cement kilndust (“CKD”), and associated methods of use.

Settable compositions may be used in a variety of subterraneanapplications. As used herein, the term “settable composition” refers toany composition that over time will set to form a hardened mass. Oneexample of a settable composition comprises hydraulic cement and water.Subterranean applications that may involve settable compositionsinclude, but are not limited to, primary cementing, remedial cementing,and drilling operations. Settable compositions also may be used insurface applications, for example, construction cementing.

Settable compositions may be used in primary cementing operationswhereby pipe strings, such as casing and liners, are cemented in wellbores. In performing primary cementing, a settable composition may bepumped into an annular space between the walls of a well bore and thepipe string disposed therein. The cement composition sets in the annularspace, thereby forming an annular sheath of hardened cement (e.g., acement sheath) that supports and positions the pipe string in the wellbore and bonds the exterior surface of the pipe string to the walls ofthe well bore.

Settable compositions also may be used in remedial cementing operations,such as sealing voids in a pipe string or a cement sheath. As usedherein the term “void” refers to any type of space, including fractures,holes, cracks, channels, spaces, and the like. Such voids may include:holes or cracks in the pipe strings; holes, cracks, spaces, or channelsin the cement sheath; and very small spaces (commonly referred to as“microannuli”) between the cement sheath and the exterior surface of thewell casing or formation. Sealing such voids may prevent the undesiredflow of fluids (e.g., oil, gas, water, etc.) and/or fine solids into, orfrom, the well bore.

The sealing of such voids, whether or not made deliberately, has beenattempted by introducing a substance into the void and permitting it toremain therein to seal the void. If the substance does not fit into thevoid, a bridge, patch, or sheath may be formed over the void to possiblyproduce a termination of the undesired fluid flow. Substances usedheretofore in methods to terminate the undesired passage of fluidsthrough such voids include settable compositions comprising water andhydraulic cement, wherein the methods employ hydraulic pressure to forcethe settable composition into the void. Once placed into the void, thesettable composition may be permitted to harden.

Remedial cementing operations also may be used to seal portions ofsubterranean formations or portions of gravel packs. The portions of thesubterranean formation may include permeable portions of a formation andfractures (natural or otherwise) in the formation and other portions ofthe formation that may allow the undesired flow of fluid into, or from,the well bore. The portions of the gravel pack include those portions ofthe gravel pack, wherein it is desired to prevent the undesired flow offluids into, or from, the well bore. A “gravel pack” is a term commonlyused to refer to a volume of particulate materials (such as sand) placedinto a well bore to at least partially reduce the migration ofunconsolidated formation particulates into the well bore. Whilescreenless gravel packing operations are becoming more common, gravelpacking operations commonly involve placing a gravel pack screen in thewell bore neighboring a desired portion of the subterranean formation,and packing the surrounding annulus between the screen and the well borewith particulate materials that are sized to prevent and inhibit thepassage of formation solids through the gravel pack with producedfluids. Among other things, this method may allow sealing of the portionof the gravel pack to prevent the undesired flow of fluids withoutrequiring the gravel pack's removal.

Settable compositions also may be used during the drilling of the wellbore in a subterranean formation. For example, in the drilling of a wellbore, it may be desirable, in some instances, to change the direction ofthe well bore. In some instances, settable compositions may be used tofacilitate this change of direction, for example, by drilling a pilothole in a hardened mass of cement, commonly referred to as a “kickoffplug,” placed in the well bore.

Certain formations may cause the drill bit to drill in a particulardirection. For example, in a vertical well, this may result in anundesirable well bore deviation from vertical. In a directional well(which is drilled at an angle from vertical), after drilling an initialportion of the well bore vertically, the direction induced by theformation may make following the desired path difficult. In those andother instances, special directional drilling tools may be used, such asa whipstock, a bent sub-downhole motorized drill combination, and thelike. Generally, the directional drilling tool or tools used may beorientated so that a pilot hole is produced at the desired angle to theprevious well bore in a desired direction. When the pilot hole has beendrilled for a short distance, the special tool or tools are removed, ifrequired, and drilling along the new path may be resumed. To help ensurethat the subsequent drilling follows the pilot hole, it may be necessaryto drill the pilot hole in a kickoff plug, placed in the well bore. Inthose instances, prior to drilling the pilot hole, a settablecomposition may be introduced into the well bore and allowed to set toform a kickoff plug therein. The pilot hole then may be drilled in thekickoff plug, and the high strength of the kickoff plug helps ensurethat the subsequent drilling proceeds in the direction of the pilothole.

Settable compositions used heretofore commonly comprise Portland cement.Portland cement generally is a major component of the cost for thesettable compositions. To reduce the cost of such settable compositions,other components may be included in the settable composition in additionto, or in place of, the Portland cement. Such components may include flyash, slag cement, shale, metakaolin, micro-fine cement, and the like.“Fly ash,” as that term is used herein, refers to the residue from thecombustion of powdered or ground coal, wherein the fly ash carried bythe flue gases may be recovered, for example, by electrostaticprecipitation. “Slag,” as that term is used herein, refers to agranulated, blast furnace by-product formed in the production of castiron and generally comprises the oxidized impurities found in iron ore.Slag cement generally comprises slag and a base, for example, such assodium hydroxide, sodium bicarbonate, sodium carbonate, or lime, toproduce a settable composition that, when combined with water, may setto form a hardened mass.

During the manufacture of cement, a waste material commonly referred toas “CKD” is generated. “CKD,” as that term is used herein, refers to apartially calcined kiln feed which is removed from the gas stream andcollected in a dust collector during the manufacture of cement. Usually,large quantities of CKD are collected in the production of cement thatare commonly disposed of as waste. Disposal of the waste CKD can addundesirable costs to the manufacture of the cement, as well as theenvironmental concerns associated with its disposal. The chemicalanalysis of CKD from various cement manufactures varies depending on anumber of factors, including the particular kiln feed, the efficienciesof the cement production operation, and the associated dust collectionsystems. CKD generally may comprise a variety of oxides, such as SiO₂,Al₂O₃, Fe₂O₃, CaO, MgO, SO₃, Na₂O, and K₂O.

SUMMARY

The present invention relates to cementing operations and, moreparticularly, to settable compositions comprising water and CKD, andassociated methods of use.

In one embodiment, the present invention provides a method of cementingcomprising: providing a foamed settable composition comprising water,CKD, a gas, and a surfactant; introducing the foamed settablecomposition into a location to be cemented; and allowing the foamedsettable composition to form a hardened mass therein.

Another embodiment of the present invention provides a method ofcementing a pipe string disposed in a well bore comprising: providing afoamed settable composition comprising water, CKD, a gas, and asurfactant; introducing the foamed settable composition into an annulusbetween the pipe string and a wall of the well bore; and allowing thefoamed settable composition to set in the annulus.

Another embodiment of the present invention provides a method ofcementing comprising: providing a settable composition comprising water,CKD, and a surfactant; foaming the settable composition with a gas toform a foamed settable composition; introducing the foamed settablecomposition into a location to be cemented; and allowing the foamedsettable composition to set therein.

The features and advantages of the present invention will be apparent tothose skilled in the art. While numerous changes may be made by thoseskilled in the art, such changes are within the spirit of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention relates to cementing operations and, moreparticularly, to settable compositions comprising water and CKD, andassociated methods of use. The settable compositions of the presentinvention may be used in a variety of subterranean applications,including primary cementing, remedial cementing, and drillingoperations. The settable compositions of the present invention also maybe used in surface applications, for example, construction cementing.

Settable Compositions of the Present Invention

In one embodiment, a settable composition of the present inventioncomprises water and CKD. In some embodiments, a settable composition ofthe present invention may be foamed, for example, comprising water, CKD,a gas, and a surfactant. A foamed settable composition may be used, forexample, where it is desired for the settable composition to belightweight. Other optional additives may also be included in thesettable compositions of the present invention as desired, including,but not limited to, hydraulic cement, fly ash, slag cement, shale,zeolite, metakaolin, combinations thereof, and the like.

The settable compositions of the present invention should have a densitysuitable for a particular application as desired by those of ordinaryskill in the art, with the benefit of this disclosure. In someembodiments, the settable compositions of the present invention may havea density in the range of from about 8 pounds per gallon (“ppg”) toabout 16 ppg. In the foamed embodiments, the foamed settablecompositions of the present invention may have a density in the range offrom about 8 ppg to about 13 ppg.

The water used in the settable compositions of the present invention mayinclude freshwater, saltwater (e.g., water containing one or more saltsdissolved therein), brine (e.g., saturated saltwater produced fromsubterranean formations), seawater, or combinations thereof. Generally,the water may be from any source, provided that it does not contain anexcess of compounds that may adversely affect other components in thesettable composition. In some embodiments, the water may be included inan amount sufficient to form a pumpable slurry. In some embodiments, thewater may be included in the settable compositions of the presentinvention in an amount in the range of from about 40% to about 200% byweight. As used herein, the term “by weight,” when used herein to referto the percent of a component in the settable composition, means byweight included in the settable compositions of the present inventionrelative to the weight of the dry components in the settablecomposition. In some embodiments, the water may be included in an amountin the range of from about 40% to about 150% by weight.

The CKD should be included in the settable compositions in an amountsufficient to provide the desired compressive strength, density, and/orcost reduction. In some embodiments, the CKD may be present in thesettable compositions of the present invention in an amount in the rangeof from about 0.01% to 100% by weight. In some embodiments, the CKD maybe present in the settable compositions of the present invention in anamount in the range of from about 5% to 100% by weight. In someembodiments, the CKD may be present in the settable compositions of thepresent invention in an amount in the range of from about 5% to about80% by weight. In some embodiments, the CKD may be present in thesettable compositions of the present invention in an amount in the rangeof from about 10% to about 50% by weight.

The settable compositions of the present invention may optionallycomprise a hydraulic cement. A variety of hydraulic cements may beutilized in accordance with the present invention, including, but notlimited to, those comprising calcium, aluminum, silicon, oxygen, iron,and/or sulfur, which set and harden by reaction with water. Suitablehydraulic cements include, but are not limited to, Portland cements,pozzolana cements, gypsum cements, high alumina content cements, slagcements, silica cements, and combinations thereof. In certainembodiments, the hydraulic cement may comprise a Portland cement. Insome embodiments, the Portland cements that are suited for use in thepresent invention are classified as Classes A, C, H, and G cementsaccording to American Petroleum Institute, API Specification forMaterials and Testing for Well Cements, API Specification 10, Fifth Ed.,Jul. 1, 1990.

Where present, the hydraulic cement generally may be included in thesettable compositions in an amount sufficient to provide the desiredcompressive strength, density, and/or cost. In some embodiments, thehydraulic cement may be present in the settable compositions of thepresent invention in an amount in the range of from 0% to about 100% byweight. In some embodiments, the hydraulic cement may be present in thesettable compositions of the present invention in an amount in the rangeof from 0% to about 95% by weight. In some embodiments, the hydrauliccement may be present in the settable compositions of the presentinvention in an amount in the range of from about 20% to about 95% byweight. In some embodiments, the hydraulic cement may be present in thesettable compositions of the present invention in an amount in the rangeof from about 50% to about 90% by weight.

In some embodiments, a pozzolana cement that may be suitable for usecomprises fly ash. A variety of fly ashes may be suitable, including flyash classified as Class C and Class F fly ash according to AmericanPetroleum Institute, API Specification for Materials and Testing forWell Cements, API Specification 10, Fifth Ed., Jul. 1, 1990. Class C flyash comprises both silica and lime so that, when mixed with water, itsets to form a hardened mass. Class F fly ash generally does not containsufficient lime, so an additional source of calcium ions is required forthe Class F fly ash to form a settable composition with water. In someembodiments, lime may be mixed with Class F fly ash in an amount in therange of from about 0.1% to about 25% by weight of the fly ash. In someinstances, the lime may be hydrated lime. Suitable examples of fly ashinclude, but are not limited to, “POZMIX® A” cement additive,commercially available from Halliburton Energy Services, Inc., Duncan,Okla.

Where present, the fly ash generally may be included in the settablecompositions in an amount sufficient to provide the desired compressivestrength, density, and/or cost. In some embodiments, the fly ash may bepresent in the settable compositions of the present invention in anamount in the range of from about 5% to about 75% by weight. In someembodiments, the fly ash may be present in the settable compositions ofthe present invention in an amount in the range of from about 10% toabout 60% by weight.

In some embodiments, a slag cement that may be suitable for use maycomprise slag. Slag generally does not contain sufficient basicmaterial, so slag cement further may comprise a base to produce asettable composition that may react with water to set to form a hardenedmass. Examples of suitable sources of bases include, but are not limitedto, sodium hydroxide, sodium bicarbonate, sodium carbonate, lime, andcombinations thereof.

Where present, the slag cement generally may be included in the settablecompositions in an amount sufficient to provide the desired compressivestrength, density, and/or cost. In some embodiments, the slag cement maybe present in the settable compositions of the present invention in anamount in the range of from 0% to about 99.9% by weight. In someembodiments, the slag cement may be present in the settable compositionsof the present invention in an amount in the range of from about 5% toabout 75% by weight.

In certain embodiments, the settable compositions of the presentinvention further may comprise metakaolin. Generally, metakaolin is awhite pozzolan that may be prepared by heating kaolin clay, for example,to temperatures in the range of from about 600° to about 800° C. In someembodiments, the metakaolin may be present in the settable compositionsof the present invention in an amount in the range of from about 5% toabout 95% by weight. In some embodiments, the metakaolin may be presentin an amount in the range of from about 10% to about 50% by weight.

In certain embodiments, the settable compositions of the presentinvention further may comprise shale. Among other things, shale includedin the settable compositions may react with excess lime to form asuitable cementing material, for example, calcium silicate hydrate. Avariety of shales are suitable, including those comprising silicon,aluminum, calcium, and/or magnesium. An example of a suitable shalecomprises vitrified shale. Suitable examples of vitrified shale include,but are not limited to, “PRESSUR-SEAL® FINE LCM” material and“PRESSUR-SEAL® COARSE LCM” material, which are commercially availablefrom TXI Energy Services, Inc., Houston, Tex. Generally, the shale mayhave any particle size distribution as desired for a particularapplication. In certain embodiments, the shale may have a particle sizedistribution in the range of from about 37 micrometers to about 4,750micrometers.

Where present, the shale may be included in the settable compositions ofthe present invention in an amount sufficient to provide the desiredcompressive strength, density, and/or cost. In some embodiments, theshale may be present in an amount in the range of from about 5% to about75% by weight. In some embodiments, the shale may be present in anamount in the range of from about 10% to about 35% by weight. One ofordinary skill in the art, with the benefit of this disclosure, willrecognize the appropriate amount of the shale to include for a chosenapplication.

In certain embodiments, the settable compositions of the presentinvention further may comprise zeolite. Zeolites generally are porousalumino-silicate minerals that may be either a natural or syntheticmaterial. Synthetic zeolites are based on the same type of structuralcell as natural zeolites, and may comprise aluminosilicate hydrates. Asused herein, the term “zeolite” refers to all natural and syntheticforms of zeolite.

In certain embodiments, suitable zeolites for use in present inventionmay include “analcime” (which is hydrated sodium aluminum silicate),“bikitaite” (which is lithium aluminum silicate), “brewsterite” (whichis hydrated strontium barium calcium aluminum silicate), “chabazite”(which is hydrated calcium aluminum silicate), “clinoptilolite” (whichis hydrated sodium aluminum silicate), “faujasite” (which is hydratedsodium potassium calcium magnesium aluminum silicate), “harmotome”(which is hydrated barium aluminum silicate), “heulandite” (which ishydrated sodium calcium aluminum silicate), “laumontite” (which ishydrated calcium aluminum silicate), “mesolite” (which is hydratedsodium calcium aluminum silicate), “natrolite” (which is hydrated sodiumaluminum silicate), “paulingite” (which is hydrated potassium sodiumcalcium barium aluminum silicate), “phillipsite” (which is hydratedpotassium sodium calcium aluminum silicate), “scolecite” (which ishydrated calcium aluminum silicate), “stellerite” (which is hydratedcalcium aluminum silicate), “stilbite” (which is hydrated sodium calciumaluminum silicate), and “thomsonite” (which is hydrated sodium calciumaluminum silicate), and combinations thereof. In certain embodiments,suitable zeolites for use in the present invention include chabazite andclinoptilolite. An example of a suitable source of zeolite is availablefrom the C2C Zeolite Corporation of Calgary, Canada.

In some embodiments, the zeolite may be present in the settablecompositions of the present invention in an amount in the range of fromabout 5% to about 65% by weight. In certain embodiments, the zeolite maybe present in an amount in the range of from about 10% to about 40% byweight.

In certain embodiments, the settable compositions of the presentinvention further may comprise a set retarding additive. As used herein,the term “set retarding additive” refers to an additive that retards thesetting of the settable compositions of the present invention. Examplesof suitable set retarding additives include, but are not limited to,ammonium, alkali metals, alkaline earth metals, metal salts ofsulfoalkylated lignins, hydroxycarboxy acids, copolymers that compriseacrylic acid or maleic acid, and combinations thereof. One example of asuitable sulfoalkylate lignin comprises a sulfomethylated lignin.Suitable set retarding additives are disclosed in more detail in U.S.Pat. No. Re. 31,190, the entire disclosure of which is incorporatedherein by reference. Suitable set retarding additives are commerciallyavailable from Halliburton Energy Services, Inc. under the tradenames“HR® 4,” “HR® 5,” HR® 7,” “HR® 12,” “HR® 15,” HR® 25,” “SCR™ 100,” and“SCR™ 500.” Generally, where used, the set retarding additive may beincluded in the settable compositions of the present invention in anamount sufficient to provide the desired set retardation. In someembodiments, the set retarding additive may be present in an amount inthe range of from about 0.1% to about 5% by weight.

Optionally, other additional additives may be added to the settablecompositions of the present invention as deemed appropriate by oneskilled in the art, with the benefit of this disclosure. Examples ofsuch additives include, but are not limited to, accelerators, weightreducing additives, heavyweight additives, lost circulation materials,filtration control additives, dispersants, and combinations thereof.Suitable examples of these additives include crystalline silicacompounds, amorphous silica, salts, fibers, hydratable clays,microspheres, pozzolan lime, latex cement, thixotropic additives,combinations thereof and the like.

An example of a settable composition of the present invention maycomprise water and CKD. As desired by one of ordinary skill in the art,with the benefit of this disclosure, such settable composition of thepresent invention further may comprise any of the above-listedadditives, as well any of a variety of other additives suitable for usein subterranean applications.

Another example of a settable composition of the present invention maycomprise water and CKD, and an additive comprising at least one of thefollowing group: fly ash; shale; zeolite; slag cement; metakaolin; andcombinations thereof. As desired by one of ordinary skill in the art,with the benefit of this disclosure, such settable composition of thepresent invention further may comprise any of the above-listedadditives, as well any of a variety of other additives suitable for usein subterranean applications.

As mentioned previously, in certain embodiments, the settablecompositions of the present invention may be foamed with a gas. In someembodiments, foamed settable compositions of the present invention maycomprise water, CKD, a gas, and a surfactant. Other suitable additives,such as those discussed previously, also may be included in the foamedsettable compositions of the present invention as desired by those ofordinary skill in the art, with the benefit of this disclosure. The gasused in the foamed settable compositions of the present invention may beany gas suitable for foaming a settable composition, including, but notlimited to, air, nitrogen, or combinations thereof. Generally, the gasshould be present in the foamed settable compositions of the presentinvention in an amount sufficient to form the desired foam. In certainembodiments, the gas may be present in the foamed settable compositionsof the present invention in an amount in the range of from about 10% toabout 80% by volume of the composition.

Where foamed, the settable compositions of the present invention furthercomprise a surfactant. In some embodiments, the surfactant comprises afoaming and stabilizing surfactant composition. As used herein, a“foaming and stabilizing surfactant composition” refers to a compositionthat comprises one or more surfactants and, among other things, may beused to facilitate the foaming of a settable composition and also maystabilize the resultant foamed settable composition formed therewith.Any suitable foaming and stabilizing surfactant composition may be usedin the settable compositions of the present invention. Suitable foamingand stabilizing surfactant compositions may include, but are not limitedto: mixtures of an ammonium salt of an alkyl ether sulfate, acocoamidopropyl betaine surfactant, a cocoamidopropyl dimethylamineoxide surfactant, sodium chloride, and water; mixtures of an ammoniumsalt of an alkyl ether sulfate surfactant, a cocoamidopropylhydroxysultaine surfactant, a cocoamidopropyl dimethylamine oxidesurfactant, sodium chloride, and water; hydrolyzed keratin; mixtures ofan ethoxylated alcohol ether sulfate surfactant, an alkyl or alkeneamidopropyl betaine surfactant, and an alkyl or alkene dimethylamineoxide surfactant; aqueous solutions of an alpha-olefinic sulfonatesurfactant and a betaine surfactant; and

combinations thereof. In one certain embodiment, the foaming andstabilizing surfactant composition comprises a mixture of an ammoniumsalt of an alkyl ether sulfate, a cocoamidopropyl betaine surfactant, acocoamidopropyl dimethylamine oxide surfactant, sodium chloride, andwater. A suitable example of such a mixture is “ZONESEAL® 2000” foamingadditive, commercially available from Halliburton Energy Services, Inc.Suitable foaming and stabilizing surfactant compositions are describedin U.S. Pat. Nos. 6,797,054, 6,547,871, 6,367,550, 6,063,738, and5,897,699, the entire disclosures of which are incorporated herein byreference.

Generally, the surfactant may be present in the foamed settablecompositions of the present invention in an amount sufficient to providea suitable foam. In some embodiments, the surfactant may be present inan amount in the range of from about 0.8% and about 5% by volume of thewater (“bvow”).

Methods of the Present Invention

The settable compositions of the present invention may be used in avariety of subterranean applications, including, but not limited to,primary cementing, remedial cementing, and drilling operations. Thesettable compositions of the present invention also may be used insurface applications, for example, construction cementing.

An example of a method of the present invention comprises providing asettable composition of the present invention comprising water and CKD;placing the settable composition in a location to be cemented; andallowing the settable composition to set therein. In some embodiments,the location to be cemented may be above ground, for example, inconstruction cementing. In some embodiments, the location to be cementedmay be in a subterranean formation, for example, in subterraneanapplications. In some embodiments, the settable compositions of thepresent invention may be foamed. As desired by one of ordinary skill inthe art, with the benefit of this disclosure, the settable compositionsof the present invention useful in this method further may comprise anyof the above-listed additives, as well any of a variety of otheradditives suitable for use in subterranean applications.

Another example of a method of the present invention is a method ofcementing a pipe string (e.g., casing, expandable casing, liners, etc.)disposed in a well bore. An example of such a method may compriseproviding a settable composition of the present invention comprisingwater and CKD; introducing the settable composition into the annulusbetween the pipe string and a wall of the well bore; and allowing thesettable composition to set in the annulus to form a hardened mass.Generally, in most instances, the hardened mass should fix the pipestring in the well bore. In some embodiments, the settable compositionsof the present invention may be foamed. As desired by one of ordinaryskill in the art, with the benefit of this disclosure, the settablecompositions of the present invention useful in this method further maycomprise any of the above-listed additives, as well any of a variety ofother additives suitable for use in subterranean application.

Another example of a method of the present invention is method ofsealing a portion of a gravel pack or a portion of a subterraneanformation. An example of such a method may comprise providing a settablecomposition of the present invention comprising water and CKD;introducing the settable composition into the portion of the gravel packor the portion of the subterranean formation; and allowing the settablecomposition to form a hardened mass in the portion. The portions of thesubterranean formation may include permeable portions of the formationand fractures (natural or otherwise) in the formation and other portionsof the formation that may allow the undesired flow of fluid into, orfrom, the well bore. The portions of the gravel pack include thoseportions of the gravel pack, wherein it is desired to prevent theundesired flow of fluids into, or from, the well bore. Among otherthings, this method may allow the sealing of the portion of the gravelpack to prevent the undesired flow of fluids without requiring thegravel pack's removal. In some embodiments, the settable compositions ofthe present invention may be foamed. As desired by one of ordinary skillin the art, with the benefit of this disclosure, the settablecompositions of the present invention useful in this method further maycomprise any of the above-listed additives, as well any of a variety ofother additives suitable for use in subterranean applications.

Another example of a method of the present invention is a method ofsealing voids located in a pipe string (e.g., casing, expandablecasings, liners, etc.) or in a cement sheath. Generally, the pipe stringwill be disposed in a well bore, and the cement sheath may be located inthe annulus between the pipe string disposed in the well bore and a wallof the well bore. An example of such a method may comprise providing asettable composition comprising water and CKD; introducing the settablecomposition into the void; and allowing the settable composition to setto form a hardened mass in the void. In some embodiments, the settablecompositions of the present invention may be foamed. As desired by oneof ordinary skill in the art, with the benefit of this disclosure, thesettable compositions of the present invention useful in this methodfurther may comprise any of the above-listed additives, as well any of avariety of other additives suitable for use in subterraneanapplications.

When sealing a void in a pipe string, the methods of the presentinvention, in some embodiments, further may comprise locating the voidin the pipe string; and isolating the void by defining a space withinthe pipe string in communication with the void; wherein the settablecomposition may be introduced into the void from the space. The void maybe isolated using any suitable technique and/or apparatus, includingbridge plugs, packers, and the like. The void in the pipe string may belocated using any suitable technique.

When sealing a void in the cement sheath, the methods of the presentinvention, in some embodiments, further may comprise locating the voidin the cement sheath; producing a perforation in the pipe string thatintersects the void; and isolating the void by defining a space withinthe pipe string in communication with the void via the perforation,wherein the settable composition is introduced into the void via theperforation. The void in the pipe string may be located using anysuitable technique. The perforation may be created in the pipe stringusing any suitable technique, for example, perforating guns. The voidmay be isolated using any suitable technique and/or apparatus, includingbridge plugs, packers, and the like.

Another example of a method of the present invention is a method ofchanging the direction of drilling a well bore. An example of such amethod may comprise providing a settable composition comprising CKD;introducing the settable composition into the well bore at a location inthe well bore wherein the direction of drilling is to be changed;allowing the settable composition to set to form a kickoff plug in thewell bore; drilling a hole in the kickoff plug; and drilling of the wellbore through the hole in the kickoff plug. In some embodiments, thesettable compositions of the present invention may be foamed. As desiredby one of ordinary skill in the art, with the benefit of thisdisclosure, the settable compositions of the present invention useful inthis method further may comprise any of the above-listed additives, aswell any of a variety of other additives suitable for use insubterranean applications.

Generally, the drilling operation should continue in the direction ofthe hole drilled through the kickoff plug. The well bore and hole in thekickoff plug may be drilled using any suitable technique, includingrotary drilling, cable tool drilling, and the like. In some embodiments,one or more oriented directional drilling tools may be placed adjacentto the kickoff plug. Suitable directional drilling tools include, butare not limited to, whip-stocks, bent sub-downhole motorized drillcombinations, and the like. The direction drilling tools then may beused to drill the hole in the kickoff plug so that the hole ispositioned in the desired direction. Optionally, the directionaldrilling tool may be removed from the well bore subsequent to drillingthe hole in the kickoff plug.

To facilitate a better understanding of the present invention, thefollowing examples of certain aspects of some embodiments are given. Inno way should the following examples be read to limit, or define, thescope of the invention.

EXAMPLE 1

A series of sample settable compositions were prepared at roomtemperature and subjected to 48-hour compressive strength tests at 140°F. in accordance with API Specification 10. The sample compositionscomprised water, Class A CKD, and Class A Portland cement.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 1 Unfoamed Compressive Strength Tests: Class A Cement and Class ACKD 48-Hour Portland Compressive Cement CKD Strength at Density Class AClass A 140° F. Sample (ppg) (% by wt) (% by wt) (psi) No. 1 14 0 100228 No. 2 15.15 25 75 701 No. 3 14.84 50 50 1,189 No. 4 15.62 75 253,360 No. 5 15.6 100 0 2,350

EXAMPLE 2

Sample Compositions No. 6 and 7 were prepared at room temperature andsubjected to thickening time and fluid loss tests at 140° F. and 240°F., respectively, in accordance with API Specification 10.

Sample Composition No. 6 comprised water, Class A Portland Cement (50%by weight), Class A CKD (50% by weight), “HALAD® 23” fluid loss controladditive (0.75% by weight), and “HR®-5” set retarder (0.25% by weight).Accordingly, Sample Composition No. 6 had a Portland cement-to-CKDweight ratio of about 50:50. This Sample had a density of 14.84 ppg.“HALAD® 23” additive is a cellulose-based fluid loss control additivethat is commercially available from Halliburton Energy Services, Inc.,Duncan, Okla. “HR®-5” retarder is a lignosulfonate set retarder that iscommercially available from Halliburton Energy Services, Inc., Duncan,Okla.

Sample Composition No. 7 comprised water, Class A Portland Cement (50%by weight), Class A CKD (50% by weight), “HALAD® 413” fluid loss controladditive (0.75% by weight), and “HR®-12” set retarder (0.3% by weight).Accordingly, Sample Composition No. 7 had a Portland cement-to-CKDweight ratio of 50:50. This Sample had a density of 14.84 ppg. “HALAD®413” additive is a grafted copolymer fluid loss control additive that iscommercially available from Halliburton Energy Services, Inc., Duncan,Okla. “HR®-12” retarder is a mixture of a lignosulfonate andhydroxycarboxy acid set retarder that is commercially available fromHalliburton Energy Services, Inc., Duncan, Okla.

The results of the fluid loss and thickening time tests are set forth inthe table below.

TABLE 2 Unfoamed Thickening Time and Fluid Loss Tests: Class A Cementand Class A CKD Cement-to- Test Thickening API Fluid CKD WeightTemperature Time to 70 BC Loss in 30 min Sample Ratio (° F.) (min:hr)(ml) No. 6 50:50 140 6:06 147 No. 7 50:50 240 2:20 220

EXAMPLE 3

A series of sample settable compositions were prepared at roomtemperature and subjected to 48-hour compressive strength tests at 140°F. in accordance with API Specification 10. The sample compositionscomprised water, Class H CKD, and Class H Portland cement.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 3 Unfoamed Compressive Strength Tests: Class H Cement and Class HCKD 48-Hour Portland Compressive Cement CKD Strength at Density Class HClass H 140° F. Sample (ppg) (% by wt) (% by wt) (psi) No. 8 15.23 0 10074.9 No. 9 15.4 25 75 544 No. 10 16 50 50 1,745 No. 11 16.4 75 25 3,250No. 12 16.4 100 0 1,931

EXAMPLE 4

Sample Compositions No. 13 and 14 were prepared at room temperature andsubjected to thickening time and fluid loss tests at 140° F. and 240°F., respectively, in accordance with API Specification 10.

Sample Composition No. 13 comprised water, Class H Portland Cement (50%by weight), Class H CKD (50% by weight), “HALAD® 23” fluid loss controladditive (0.75% by weight), and 0.25% by weight “HR®-5” set retarder(0.25% by weight). Accordingly, Sample Composition No. 13 had a Portlandcement-to-CKD weight ratio of about 50:50. This Sample had a density of16 ppg.

Sample Composition No. 14 comprised water, Class H Portland Cement (50%by weight), Class H CKD (50% by weight), “HALAD® 413” fluid loss controladditive (0.75% by weight), and “HR®-12” set retarder (0.3% by weight).Accordingly, Sample Composition No. 14 had a Portland cement-to-CKDweight ratio of about 50:50. This Sample had a density of 16 ppg.

The results of the fluid loss and thickening time tests are set forth inthe table below.

TABLE 4 Unfoamed Thickening Time and Fluid Loss Tests: Class H Cementand Class H CKD Cement-to- Test Thickening API Fluid CKD WeightTemperature Time to 70 BC Loss in 30 min Sample Ratio (° F.) (min:hr)(ml) No. 13 50:50 140 5:04 58 No. 14 50:50 240 1:09 220

EXAMPLE 5

A series of sample settable compositions were prepared at roomtemperature and subjected to 48-hour compressive strength tests at 140°F. in accordance with API Specification 10. The sample compositionscomprised water, Class G CKD, and Class G Portland cement.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 5 Unfoamed Compressive Strength Tests: Class G Cement and Class GCKD 48-Hour Portland Compressive Cement CKD Strength at Density Class GClass G 140° F. Sample (ppg) (% by wt) (% by wt) (psi) No. 15 14.46 0100 371 No. 16 14.47 25 75 601 No. 17 14.49 50 50 1,100 No. 18 14.46 7525 3,160 No. 19 14.46 100 0 3,880

EXAMPLE 6

Sample Compositions No. 20 and 21 were prepared at room temperature andsubjected to thickening time and fluid loss tests at 140° F. and 240°F., respectively, in accordance with API Specification 10.

Sample Composition No. 20 comprised water, Class G Portland Cement (50%by weight), Class G CKD (50% by weight), “HALAD® 23” fluid loss controladditive (0.75% by weight), and “HR®-5” set retarder (0.25% by weight).Accordingly, Sample Composition No. 20 had a Portland cement-to-CKDweight ratio of about 50:50. This Sample had a density of 15.23 ppg.

Sample Composition No. 21 comprised water, Class G Portland Cement (50%by weight), Class G CKD (50% by weight), “HALAD® 413” fluid loss controladditive (0.75% by weight), and “HR®-12” set retarder (0.3% by weight).Accordingly, Sample Composition No. 21 had a Portland cement-to-CKDweight ratio of about 50:50. This Sample had a density of 15.23 ppg.

The results of the fluid loss and thickening time tests are set forth inthe table below.

TABLE 6 Unfoamed Thickening Time and Fluid Loss Tests: Class G Cementand Class G CKD Cement-to- Test Thickening API Fluid CKD WeightTemperature Time to 70 BC Loss in 30 min Sample Ratio (° F.) (min:hr)(ml) No. 20 50:50 140 3:19 132 No. 21 50:50 240 1:24 152

Accordingly, Examples 1-6 indicate that settable compositions comprisingPortland cement and CKD may have suitable thickening times, compressivestrengths, and/or fluid loss properties for a particular application.

EXAMPLE 7

A series of foamed sample compositions were prepared in accordance withthe following procedure. For each sample, a base sample composition wasprepared that comprised water, Class A Portland cement, and Class A CKD.The amounts of CKD and Portland cement were varied as shown in the tablebelow. “ZONESEAL® 2000” foaming additive was then added to each basesample composition in an amount of 2% bvow. Next, each base samplecomposition was foamed down to about 12 ppg. After preparation, theresulting foamed sample compositions were subjected to 72-hourcompressive strength tests at 140° F. in accordance with APISpecification 10.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 7 Foamed Compressive Strength Test: Class A Cement and Class A CKD72-Hour Portland Compressive Base Foam Cement CKD Strength at DensityDensity Class A Class A 140° F. Sample (ppg) (ppg) (% by wt) (% by wt)(psi) No. 22 14.34 12 0 100 167.6 No. 23 14.15 12 25 75 701 No. 24 15.0312 50 50 1,253 No. 25 15.62 12 75 25 1,322 No. 26 15.65 12 100 0 1,814

EXAMPLE 8

A series of foamed sample compositions were prepared in accordance withthe following procedure. For each sample, a base sample composition wasprepared that comprised water, Class H Portland cement, and Class H CKD.The amounts of CKD and Portland cement were varied as shown in the tablebelow. “ZONESEAL® 2000” foaming additive was then added to each basesample composition in an amount of 2% bvow. Next, each base samplecomposition was foamed down to about 12 ppg. After preparation, theresulting foamed sample compositions were subjected to 72-hourcompressive strength tests at 140° F. in accordance with APISpecification 10.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 8 Foamed Compressive Strength Tests: Class H Cement and Class HCKD 72-Hour Portland Compressive Base Foam Cement CKD Strength atDensity Density Class H Class H 140° F. Sample (ppg) (ppg) (% by wt) (%by wt) (psi) No. 27 15.07 12 0 100 27.2 No. 28 15.4 12 25 75 285 No. 2916 12 50 50 845 No. 30 16.4 12 75 25 1,458 No. 31 16.57 12 100 0 1,509

EXAMPLE 9

A series of foamed sample compositions were prepared in accordance withthe following procedure. For each sample, a base sample composition wasprepared that comprised water, Class G Portland cement, and Class G CKD.The amounts of CKD and Portland cement were varied as shown in the tablebelow. “ZONESEAL® 2000” foaming additive was then added to each basesample composition in an amount of 2% bvow. Next, each base samplecomposition was foamed down to about 12 ppg. After preparation, theresulting foamed sample compositions were subjected to 72-hourcompressive strength tests at 140° F. in accordance with APISpecification 10.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 9 Foamed Compressive Strength Tests: Class G Cement and Class GCKD 72-Hour Portland Compressive Base Foam Cement CKD Strength atDensity Density Class G Class G 140° F. Sample (ppg) (ppg) (% by wt) (%by wt) (psi) No. 32 14.32 12 0 100 181 No. 33 14.61 12 25 75 462 No. 3415 12 50 50 729 No. 35 15.43 12 75 25 1,196 No. 36 15.91 12 100 0 1,598

Accordingly, Examples 7-9 indicate that foamed settable compositionscomprising Portland cement and CKD may have suitable compressivestrengths for a particular application.

EXAMPLE 10

A series of sample settable compositions were prepared at roomtemperature and subjected to 24-hour compressive strength tests at 140°F. in accordance with API Specification 10. Sufficient water wasincluded in each sample to provide a density of about 14.2 ppg.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 10 Unfoamed Compressive Strength Tests Class A Cement, Class ACKD, Shale, Fly Ash, and Lime 24-Hour Portland Compressive Cement CKDVitrified POZMIZ ® A Hydrated Strength at Class A Class A Shale¹Additive Lime 140° F. Sample (% by wt) (% by wt) (% by wt) (% by wt) (%by wt) (psi) No. 37 26 0 0 61 13 1,024 No. 38 19.5 6.5 0 61 13 766 No.39 20.7 5.3 0 61 13 825 No. 40 23.3 2.7 0 61 13 796 No. 41 19.4 3.3 3.361 13 717 No. 42 20.7 2.65 2.65 61 13 708 No. 43 23.3 1.35 1.35 61 13404 ¹The vitrified shale used was “PRESSUR-SEAL ® FINE LCM” material.

EXAMPLE 11

A series of sample compositions were prepared and subjected tothickening time tests at 140° F. in accordance with API Specification10.

Sample Composition No. 44 comprised water, Class A Portland Cement (26%by weight), “POZMIX® A” cement additive (61% by weight), hydrated lime(13% by weight), “HALAD® 23” fluid loss control additive (0.6% byweight), and “HR®-5” set retarder (0.1% by weight). This Sample had adensity of 14.2 ppg.

Sample Composition No. 45 comprised water, Class A Portland Cement(19.5% by weight), Class A CKD (6.5% by weight), “POZMIX® A” cementadditive (61% by weight), hydrated lime (13% by weight), “HALAD® 23”fluid loss control additive (0.6% by weight), and “HR®-5” set retarder(0.1% by weight). This Sample had a density of 14.2 ppg. The vitrifiedshale was “PRESSUR-SEAL® FINE LCM” material.

Sample Composition No. 46 comprised water, Class A Portland Cement(19.5% by weight), Class A CKD (3.25% by weight), vitrified shale (3.25%by weight), “POZMIX® A” cement additive (61% by weight), hydrated lime(13% by weight), “HALAD® 23” fluid loss control additive (0.6% byweight), and “HR®-5” set retarder (0.1% by weight). This Sample had adensity of 14.2 ppg. The vitrified shale was “PRESSUR-SEAL® FINE LCM”material.

The results of the fluid loss and thickening time tests are set forth inthe table below.

TABLE 11 Unfoamed Thickening Time Tests: Class A Cement, Class A CKD,Shale, Fly ash, and Lime Portland Thickening Cement CKD VitrifiedPOZMIX ® A Hydrated Time to 70 Class A Class A Shale¹ Additive Lime BCat 140° F. Sample (% by wt) (% by wt) (% by wt) (% by wt) (% by wt)(min:hr) No. 44 26 0 0 61 13 2:57 No. 45 19.5 6.5 0 61 13 2:20 No. 4619.5 2.25 2.25 61 13 3:12 ¹The vitrified shale used was “PRESSUR-SEAL ®FINE LCM” material.

EXAMPLE 12

A series of sample settable compositions were prepared at roomtemperature and subjected to 24-hour compressive strength tests at 140°F. in accordance with API Specification 10. Sufficient water wasincluded in each sample to provide a density of about 14.2 ppg.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 12 Unfoamed Compressive Strength Tests: Class H Cement, Class HCKD, Shale, Fly ash, and Lime 24-Hour Portland Compressive Cement CKDVitrified POZMIX ® A Hydrated Strength at Class H Class H Shale¹Additive Lime 140° F. Sample (% by wt) (% by wt) (% by wt) (% by wt) (%by wt) (psi) No. 47 26 0 0 61 13 704 No. 48 19.5 6.5 0 61 13 576 No. 4920.7 5.3 0 61 13 592 No. 50 23.3 2.7 0 61 13 627 No. 51 19.4 3.3 3.3 6113 626 No. 52 20.7 2.65 2.65 61 13 619 No. 53 23.3 1.35 1.35 61 13 594¹The vitrified shale used was “PRESSUR-SEAL ® FINE LCM” material.

EXAMPLE 13

Sample Composition No. 54 was prepared and subjected to a fluid losstest at 140° F. in accordance with API Specification 10. SampleComposition No. 54 comprised water, Class H Portland Cement (19.5% byweight), Class H CKD (3.3% by weight), vitrified shale (3.3% by weight),“POZMIX® A” cement additive (61% by weight), hydrated lime (13% byweight), “HALAD® 23” fluid loss control additive (0.6% by weight), and“HR®-5” set retarder (0.1% by weight). This Sample had a density of 14.2ppg. Accordingly, Sample Composition No. 54 had a Portland cement-to-CKDweight ratio of 75:25. The vitrified shale was “PRESSUR-SEAL® FINE LCM”material.

The result of this fluid loss test is set forth in the table below.

TABLE 13 Unfoamed Fluid Loss Test: Class H Cement, Class H CKD, Shale,Fly ash, and Lime Portland Fluid Loss in Cement CKD Vitrified POZMIX ® AHydrated 30 min API Class H Class H Shale¹ Additive Lime at 140° F.Sample (% by wt) (% by wt) (% by wt) (% by wt) (% by wt) (ml) No. 5419.5 3.3 3.3 61 13 117 ¹The vitrified shale used was “PRESSUR-SEAL ®FINE LCM” material.

EXAMPLE 14

A series of sample settable compositions were prepared at roomtemperature and subjected to 24-hour compressive strength tests at 140°F. in accordance with API Specification 10. Sufficient water wasincluded in each sample to provide a density of about 14.2 ppg.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 14 Unfoamed Compressive Strength Tests: Class G Cement, Class GCKD, Shale, Fly ash, and Lime 24-Hour Portland Compressive Cement CKDVitrified POZMIX ® A Hydrated Strength at Class G Class G Shale¹Additive Lime 140° F. Sample (% by wt) (% by wt) (% by wt) (% by wt) (%by wt) (psi) No. 55 26 0 0 61 13 491 No. 56 19.5 6.5 0 61 13 526 No. 5720.7 5.3 0 61 13 474 No. 58 23.3 2.7 0 61 13 462 No. 59 19.4 3.3 3.3 6113 523 No. 60 20.7 2.65 2.65 61 13 563 ¹The vitrified shale used was“PRESSUR-SEAL ® FINE LCM” material.

Accordingly, Examples 10-14 indicate that settable compositionscomprising Portland cement, CKD, fly ash, hydrated lime, and optionallyvitrified shale may have suitable compressive strengths, thickeningtimes, and/or fluid loss properties for a particular application.

EXAMPLE 15

A series of foamed sample compositions were prepared in accordance withthe following procedure. For each sample, a base sample composition wasprepared that comprised water, Class A Portland cement, Class A CKD,vitrified shale, “POZMIX® A” cement additive (61% by weight), andhydrated lime (13% by weight). This Sample had a density of 14.2 ppg.The vitrified shale used was “PRESSUR-SEAL® FINE LCM” material. Theamounts of CKD, Portland cement, and vitrified shale were varied asshown in the table below. “ZONESEAL® 2000” foaming additive was thenadded to each base sample composition in an amount of 2% bvow. Next,each base sample composition was foamed down to about 12 ppg. Afterpreparation, the resulting foamed sample compositions were subjected to10-day compressive strength tests at 140° F. in accordance with APISpecification 10.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 15 Foamed Compressive Strength Tests: Class A Cement, Class A CKD,Shale, Fly ash, and Lime 10-Day Portland Compressive Cement CKDVitrified POZMIX ® A Hydrated Strength at Class A Class A Shale¹Additive Lime 140° F. Sample (% by wt) (% by wt) (% by wt) (% by wt) (%by wt) (psi) No. 61 26 0 0 61 13 1,153 No. 62 19.5 6.5 0 61 13 1,151 No.63 20.7 5.3 0 61 13 1,093 No. 64 23.3 2.7 0 61 13 950 No. 65 19.4 3.33.3 61 13 1,161 No. 66 20.7 2.65 2.65 61 13 1,009 No. 67 23.3 1.35 1.3561 13 1,231 ¹The vitrified shale used was “PRESSUR-SEAL ® FINE LCM”material.

EXAMPLE 16

A series of foamed sample compositions were prepared in accordance withthe following procedure. For each sample, a base sample composition wasprepared that comprised water, Class A Portland cement, Class A CKD,vitrified shale, “POZMIX® A” cement additive (61% by weight), andhydrated lime (13% by weight). This Sample had a density of 14.2 ppg.The vitrified shale used was “PRESSUR-SEAL® FINE LCM” material. Theamounts of CKD, Portland cement, and vitrified shale were varied asshown in the table below. “ZONESEAL® 2000” foaming additive was thenadded to each base sample composition in an amount of 2% bvow. Next,each base sample composition was foamed down to about 12 ppg. Afterpreparation, the resulting foamed sample compositions were subjected to72-hour compressive strength tests at 140° F. in accordance with APISpecification 10.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 16 Foamed Compressive Strength Tests: Class A Cement, Class A CKD,Shale, Fly Ash, and Lime 72-Hour Portland Compressive Cement CKDVitrified POZMIX ® A Hydrated Strength at Class A Class A Shale¹Additive Lime 140° F. Sample (% by wt) (% by wt) (% by wt) (% by wt) (%by wt) (psi) No. 68 26 0 0 61 13 1,057 No. 69 19.5 6.5 0 61 13 969 No.70 20.7 5.3 0 61 13 984 No. 71 19.4 3.3 3.3 61 13 921 No. 72 20.7 2.652.65 61 13 811 No. 73 23.3 1.35 1.35 61 13 969 ¹The vitrified shale usedwas “PRESSUR-SEAL ® FINE LCM” material.

EXAMPLE 17

Foamed Sample Composition No. 74 was prepared in accordance with thefollowing procedure. A base sample composition was prepared thatcomprised water, Class G Portland cement (19.5% by weight), Class G CKD(6.5% by weight), “POZMIX® A” cement additive (61% by weight), andhydrated lime (13% by weight). This base sample had a density of 14.2ppg. “ZONESEAL® 2000” foaming additive was then added to each basesample composition in an amount of 2% bvow. Next, the base sample wasfoamed down to about 12 ppg. After preparation, the resulting FoamedSample Composition was subjected to a 72-hour compressive strength testat 140° F. in accordance with API Specification 10.

The result of the compressive strength test is set forth in the tablebelow.

TABLE 17 Foamed Compressive Strength Tests: Class G Cement, Class G CKD,Fly Ash, and Lime 72-Hour Portland Compressive Cement CKD POZMIX ® AHydrated Strength at Class G Class G Additive Lime 140° F. Sample (bywt) (by wt) (by wt) (by wt) (psi) No. 74 19.5 6.5 61 13 777

Accordingly, Examples 15-17 indicate that foamed settable compositionscomprising Portland cement, CKD, fly ash, hydrated lime, and optionallyvitrified shale may have suitable compressive strengths for a particularapplication.

EXAMPLE 18

A series of sample settable compositions were prepared at roomtemperature and subjected to 24-hour compressive strength tests at 180°F. in accordance with API Specification 10. The sample compositionscomprised water, Class A CKD, Class A Portland cement, zeolite,vitrified shale, and hydrated lime. The vitrified shale used was“PRESSUR-SEAL® FINE LCM” material. The amount of each component wasvaried as shown in the table below.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 18 Unfoamed Compressive Strength Tests: Class A Cement, Class ACKD, Zeolite, Shale, and Lime 24-Hour Portland Compressive Cement CKDVitrified Hydrated Strength at Density Class A Class A Zeolite Shale¹Lime 180° F. Sample (ppg) (% by wt) (% by wt) (% by wt) (% by wt) (% bywt) (psi) No. 75 13.3 50 25 25 0 0 1,915 No. 76 12.75 50 25 12.5 12.5 02,190 No. 77 11.6 0 75 10 25 0 31.6 No. 78 12.8 25 50 23.5 0 0 875 No.79 12.5 25 50 12.5 12.5 0 923 No. 80 11.5 0 70 10 15 5 116.4 ¹Thevitrified shale used was “PRESSUR-SEAL ® FINE LCM” material.

EXAMPLE 19

Foamed Sample Composition No. 81 was prepared in accordance with thefollowing procedure. A base sample composition was prepared thatcomprised water, Class A Portland cement, Class A CKD, and zeolite. Thisbase sample had a density of 14.2 ppg. “ZONESEAL® 2000” foaming additivewas then added in an amount of 2% bvow. Next, the base sample was foameddown to about 12 ppg. After preparation, the resulting Foamed SampleComposition was subjected to a 72-hour compressive strength test at 140°F. in accordance with API Specification 10.

The result of the compressive strength test is set forth in the tablebelow.

TABLE 19 Foamed Compressive Strength Tests: Class A Cement, Class A CKD,and Zeolite 72-Hour Portland CKD Compressive Base Foam Cement Class AZeolite Strength at Density Density Class A (% (% 140° F. Sample (ppg)(ppg) (% by wt) by wt) by wt) (psi) No. 81 13.35 12 50 25 25 972

EXAMPLE 20

Sample Composition No. 82 was prepared at room temperature and subjectedto a 24-hour compressive strength test at 180° F. in accordance with APISpecification 10. Sample Composition No. 82 comprised water, PortlandClass H Cement, Class H CKD, Zeolite, and vitrified shale. The vitrifiedshale used was “PRESSUR-SEAL® FINE LCM” material.

The result of the compressive strength test is set forth in the tablebelow.

TABLE 20 Unfoamed Compressive Strength Tests: Class H Cement, Class HCKD, Zeolite and Shale 24-Hour Compressive Portland Cement CKD VitrifiedStrength at Density Class H Class H Zeolite Shale¹ 180° F. Sample (ppg)(% by wt) (% by wt) (% by wt) (% by wt) (psi) No. 82 15.2 50 25 12.512.5 2,280 ¹The vitrified shale used was “PRESSUR-SEAL ® FINE LCM”material.

EXAMPLE 21

Sample Composition No. 83 was prepared at room temperature and subjectedto thickening time and fluid loss tests at 140° F. in accordance withAPI Specification 10. Sample Composition No. 83 comprised Class APortland Cement (50% by weight), Class A CKD (25% by weight), zeolite(12.5% by weight), vitrified shale (12.5% by weight), “HALAD® 23” fluidloss control additive (0.75% by weight), and “HR®-5” set retarder (0.5%by weight). This Sample had a density of 12.75 ppg. The vitrified shaleused was “PRESSUR-SEAL® FINE LCM” material.

The results of the fluid loss and thickening time tests are set forth inthe table below.

TABLE 21 Unfoamed Thickening Time and Fluid Loss Tests: Class A Cement,Class A CKD, Zeolite and Shale Portland Thickening Fluid Loss CementVitrified Time to 70 in 30 min Class A CKD Class A Zeolite Shale¹ BC at140° F. at 140° F. Sample (% by wt) (% by wt) (% by wt) (% by wt)(min:hr) (ml) No. 83 50 25 12.5 12.5 8:54 196 ¹The vitrified shale usedwas “PRESSUR-SEAL ® FINE LCM” material.

Accordingly, Examples 18-21 indicate that foamed and unfoamed settablecompositions comprising Portland cement, CKD, zeolite, and optionallyvitrified shale may have suitable compressive strengths for a particularapplication.

EXAMPLE 22

A series of sample settable compositions were prepared at roomtemperature and subjected to 24-hour compressive strength tests at 190°F. in accordance with API Specification 10. The sample compositionscomprised water, slag cement, Class H CKD, Class H Portland cement,sodium carbonate, and hydrated lime. The slag cement contained sodiumcarbonate in an amount of 6% by weight. The amount of each component wasvaried as shown in the table below.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 22 Unfoamed Compressive Strength Tests: Class H Cement, Class HCKD, Slag Cement, and Lime 24-Hour Compressive Portland Cement SlagHydrated Strength at Density Class H CKD Class H Cement Lime 190° F.Sample (ppg) (% by wt) (% by wt) (% by wt) (% by wt) (psi) No. 84 13.2 050 45 5 123.6 No. 85 13.6 0 50 50 0 170.3 No. 86 14 30 50 20 0 183.2 No.87 15 30 20 50 0 563

EXAMPLE 23

A series of foamed sample settable compositions were prepared at roomtemperature and subjected to 72-hour compressive strength tests at 140°F. in accordance with API Specification 10. For each sample, a basesample composition comprised water, slag cement, Class H CKD, Class HPortland cement, and hydrated lime. The amount of each component wasvaried as shown in the table below. The slag cement contained sodiumcarbonate in an amount of 6% by weight. “ZONESEAL® 2000” foamingadditive was then added to each base sample composition in an amount of2% bvow. Next, each base sample composition was foamed down to about 11ppg. After preparation, the resulting Foamed Sample Composition wassubjected to a 72-hour compressive strength test at 140° F. inaccordance with API Specification 10.

The result of the compressive strength tests are set forth in the tablebelow.

TABLE 23 Foamed Compressive Strength Tests: Class H Cement, Class H CKD,Slag Cement, and Lime 72-Hour Portland Compressive Base Foam Cement CKDSlag Hydrated Strength at Density Density Class H Class H Cement Lime140° F. Sample (ppg) (ppg) (% by wt) (% by wt) (% by wt) (% by wt) (psi)No. 88 13.63 11 0 50 45 5 148.9 No. 89 13.68 11 0 50 50 0 161.1 No. 9014.07 11 30 50 20 0 125

Accordingly, Examples 22-23 indicate that foamed and unfoamed settablecompositions comprising CKD, slag cement, optionally hydraulic cement,and optionally hydrated lime may have suitable compressive strengths fora particular application.

EXAMPLE 24

A series of sample settable compositions were prepared at roomtemperature and subjected to 24-hour compressive strength tests at 180°F. in accordance with API Specification 10. The sample compositionscomprised water, Portland Cement, CKD, metakaolin, and vitrified shale.The amount of each component was varied as shown in the table below. Thevitrified shale used was “PRESSUR-SEAL® FINE LCM” material. Class APortland Cement was used for this series of tests, except that Class HPortland Cement was used in Sample No. 93. Class A CKD was used for thisseries of tests, except that Class H CKD was used in Sample No. 93.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 24 Compressive Strength Tests: Cement CKD, Metakaolin, and Shale24-Hour Compressive Vitrified Strength at Density Portland Cement CKDMetakaolin Shale¹ 180° F. Sample (ppg) (% by wt) (% by wt) (% by wt) (%by wt) (psi) No. 91 12.75 50 25 12.5 12.5 1,560 No. 92 13.5 50 25 25 01,082 No. 93 13 25 50 12.5 12.5 1,410 ¹The vitrified shale used was“PRESSUR-SEAL ® FINE LCM” material.

EXAMPLE 25

A series of foamed sample settable compositions were prepared at roomtemperature and subjected to 72-hour compressive strength tests at 180°F. in accordance with API Specification 10. For each sample, a basesample composition was prepared that comprised water, Portland Cement,CKD, metakaolin, and vitrified shale. The amount of each component wasvaried as shown in the table below. The vitrified shale used was“PRESSUR-SEAL® FINE LCM” material. Class A Portland Cement was used forthis series of tests, except that Class H Portland Cement was used inSample No. 96. Class A CKD was used for this series of tests, exceptthat Class H CKD was used in Sample No. 96. “ZONESEAL®2000” foamingadditive was then added to each base sample composition in an amount of2% bvow. Next, each base sample composition was foamed down to thedensity shown in the table below.

The results of the compressive strength tests are set forth in the tablebelow.

TABLE 25 Foamed Compressive Strength Tests: Cement, CKD, Metakaolin, andShale 72-Hour Base Foam Portland Vitrified Compressive Density DensityCement CKD Metakaolin Shale¹ Strength at 180° F. Sample (ppg) (ppg) (%by wt) (% by wt) (% by wt) (% by wt) (psi) No. 94 12.75 9.85 50 25 12.512.5 651 No. 95 13.5 9.84 50 25 25 0 512 No. 96 13 9.57 25 50 12.5 12.5559 ¹The vitrified shale used was “PRESSUR-SEAL ® FINE LCM” material.

Accordingly, Examples 24-25 indicate that foamed and unfoamed settablecompositions comprising hydraulic cement, CKD, metakaolin, andoptionally vitrified shale may have suitable compressive strengths for aparticular application.

Therefore, the present invention is well adapted to attain the ends andadvantages mentioned as well as those that are inherent therein. Whilenumerous changes may be made by those skilled in the art, such changesare encompassed within the spirit of this invention as defined by theappended claims. The terms in the claims have their plain, ordinarymeaning unless otherwise explicitly and clearly defined by the patentee.

1. A method of cementing comprising: providing a foamed settablecomposition comprising water, cement kiln dust, a gas, and a surfactant;introducing the foamed settable composition into a location to becemented; and allowing the foamed settable composition to form ahardened mass therein.
 2. The method of claim 1 wherein the watercomprises at least one of the following group: freshwater; saltwater; abrine; seawater; and combinations thereof.
 3. The method of claim 1wherein the cement kiln dust is present in the foamed settablecomposition in an amount in the range of about 5% to 100% by weight. 4.The method of claim 1 wherein the foamed settable composition furthercomprises a hydraulic cement.
 5. The method of claim 4 wherein thehydraulic cement is present in the foamed settable composition in anamount in the range of from about 0% to about 95% by weight.
 6. Themethod of claim 1 wherein the foamed settable composition furthercomprises at least one of the following group: fly ash; shale; zeolite;slag cement; metakaolin; and combinations thereof.
 7. The method ofclaim 1 wherein the gas comprises at least one of the following group:air; nitrogen; and combinations thereof.
 8. The method of claim 1wherein the surfactant comprises a foaming and stabilizing surfactantcomposition.
 9. The method of claim 8 wherein the foaming andstabilizing surfactant composition comprises at least one of thefollowing group: a mixture of an ammonium salt of an alkyl ethersulfate, a cocoamidopropyl betaine surfactant, a cocoamidopropyldimethylamine oxide surfactant, sodium chloride, and water; a mixture ofan ammonium salt of an alkyl ether sulfate surfactant, a cocoamidopropylhydroxysultaine surfactant, a cocoamidopropyl dimethylamine oxidesurfactant, sodium chloride, and water; a hydrolyzed keratin; a mixtureof an ethoxylated alcohol ether sulfate surfactant, an alkyl or alkeneamidopropyl betaine surfactant, and an alkyl or alkene dimethylamineoxide surfactant; an aqueous solution of an alpha-olefinic sulfonatesurfactant and a betaine surfactant; and combinations thereof.
 10. Themethod of claim 1 wherein the foamed settable composition furthercomprises at least one of the following group: a set retarding additive;an accelerator; a lost circulation material; a filtration controladditive; and combinations thereof.
 11. The method of claim 1: whereinthe cement kiln dust is present in the foamed settable composition in anamount in the range of from about 10% to about 50% by weight; whereinthe foamed settable composition further comprises Portland cement in anamount in the range of from about 50% to about 90% by weight; whereinthe surfactant comprises a mixture of an ammonium salt of an alkyl ethersulfate, a cocoamidopropyl betaine surfactant, a cocoamidopropyldimethylamine oxide surfactant, sodium chloride, and water; and whereinthe surfactant is present in the foamed settable composition in anamount in the range of from about 0.8% to about 5% by volume of thewater present in the foamed settable composition.
 12. The method ofclaim 1 wherein the location to be cemented is above ground or within asubterranean formation.
 13. The method of claim 1 wherein the step ofintroducing the foamed settable composition into the location to becemented comprises: introducing the foamed settable composition into anannulus between pipe string disposed in a well bore and a wall of thewell bore.
 14. The method of claim 1 wherein the step of introducing thefoamed settable composition into the location to be cemented comprises:introducing the foamed settable composition into a portion of a gravelpack or a portion of a subterranean formation wherein hardened massseals the portion of the gravel pack or the portion of the subterraneanformation.
 15. The method of claim 1 wherein the step of introducing thefoamed settable composition into the location to be cemented comprises:introducing the foamed settable composition into a void in a pipe stringdisposed in a well bore or in a cement sheath located in an annulusbetween the pipe string and a wall of the well bore wherein the hardenedmass seals the void.
 16. The method of claim 1 further comprising:drilling a hole in the hardened mass, wherein the hardened mass islocated in a subterranean formation; and drilling of a well bore throughthe hole in the hardened mass.
 17. A method of cementing a pipe stringdisposed in a well bore comprising: providing a foamed settablecomposition comprising water, cement kiln dust, a gas, and a surfactant;introducing the foamed settable composition into an annulus between thepipe string and a wall of the well bore; and allowing the foamedsettable composition to set in the annulus.
 18. The method of claim 17wherein the foamed settable composition further comprises at least oneof the following group: a hydraulic cement; fly ash; shale; zeolite;slag cement; metakaolin; and combinations thereof.
 19. The method ofclaim 17: wherein the cement kiln dust is present in the foamed settablecomposition in an amount in the range of from about 10% to about 50% byweight; wherein the foamed settable composition further comprisesPortland cement in an amount in the range of from about 50% to about 90%by weight; wherein surfactant comprises a mixture an ammonium salt of analkyl ether sulfate, a cocoamidopropyl betaine surfactant, acocoamidopropyl dimethylamine oxide surfactant, sodium chloride, andwater; and wherein the surfactant is present in the foamed settablecomposition in an amount in the range of from about 0.8% to about 5% byvolume of the water present in the foamed settable composition.
 20. Themethod of claim 17 wherein the hardened mass fixes the pipe string inthe well bore.
 21. A method of cementing comprising: providing asettable composition comprising water, cement kiln dust, and asurfactant; foaming the settable composition with a gas to form a foamedsettable composition; introducing the foamed settable composition into alocation to be cemented; and allowing the foamed settable composition toset therein.
 22. The method of claim 21 wherein the foamed settablecomposition further comprises at least one of the following group: ahydraulic cement; fly ash; shale; zeolite; slag cement; metakaolin; andcombinations thereof.
 23. The method of claim 21: wherein the cementkiln dust is present in the foamed settable composition in an amount inthe range of from about 10% to about 50% by weight; wherein the foamedsettable composition further comprises Portland cement in an amount inthe range of from about 50% to about 90% by weight; wherein thesurfactant comprises a mixture an ammonium salt of an alkyl ethersulfate, a cocoamidopropyl betaine surfactant, a cocoamidopropyldimethylamine oxide surfactant, sodium chloride, and water; and whereinthe surfactant is present in the foamed settable composition in anamount in the range of from about 0.8% to about 5% by volume of thewater present in the foamed settable composition.